Fluorescence detection of nucleic acids and proteins is carried out by a variety of apparatuses and methods, including capillary electrophoresis, deoxyribonucleic acid (DNA) sequencing with fluorescent dyes, and microfluidic fluorescence detection. Methods and apparatus for fluorescence detection of nucleic acids and proteins generally include four common elements: a light source for excitation of fluorophores, a fluorophore capable of excitation and emission, filters to isolate a wavelength emitted from an excited fluorophore, and a detector that detects the emitted wavelength from the excited fluorophore and produces an electrically recordable output.
When methods and apparatus of fluorescence detection are used for nucleic acid detection, such methods may require polymerase chain reaction (PCR) or isothermal amplification to obtain the desired output signal. The fluorescence detection apparatus generally includes a heating block having one or more sample wells configured for receiving vessels where PCR or isothermal amplification may take place. In instances where the heating block has at least two wells, a movable scanning component may be necessary where either the heating block or the detector is moved in order to measure the fluorescence of a sample in each of the different sample wells. Typically, the movable scanning component contains dichroic mirrors, filter wheels, and photomultiplier tubes to direct, isolate, and convert the fluorescence emissions from the samples to an electric output. These components are costly and limit the simultaneous detection of multiple wavelengths. Detection of a single fluorescent emission wavelength increases the time required for measuring fluorescent emission wavelengths from multiple sample wells, thereby decreasing efficiency and increasing the time required to complete the analysis of multiple sample wells.
It is desirable to eliminate expensive parts from the movable scanning component used in fluorescence detection. It is also desirable to provide a fluorescence detection system capable of detecting at least four fluorescent emission wavelength emissions simultaneously or nearly simultaneously.